The cyclopropane carboxylic acids represented by the above formula (I) constitutes the acid moiety of a low toxic and rapidly acting insecticidal ester generally termed pyrethroid such as allethrin, permethrin, decamethrin, teffuluthrin, etc.
The cyclopropane carboxylic acids represented by the formula (I) contain two asymmetric carbon atoms at the 1-position and the 3-position and therefore have four diastereomers. Of these isomers, those having the absolute configurations of "1R, 3S" and "1R and 3R" are termed "(+)-cis isomer" and "(+)-trans isomer" (according to RS nomenclature), respectively, because the optical rotation of these isomers is (+) in a specific solvent and substitution groups of them are in a cis-form and a trans-form, respectively. And, the other two isomers having the absolute configurations of "1S, 3S" and "1S, 3R" are termed "(-)-cis isomer" and "(-)-trans isomer", respectively, because the optical rotation of these isomers is (-) in a specific solvent and substitution group of them are in a cis-form and a trans-form, respectively. Only the (+)-isomers have insecticidal activities as pyrethroid esters and the (-)-isomers have almost no insecticidal activities as pyrethroids.
The relative effects of the cis and the trans isomers vary according to the kinds of harmful insects to be killed and the type of effect.
It is possible to use the (+)-trans-pyrethroidal compound and (+)-cis- compound independently for different purposes. Accordingly, the production of (+)-cyclopropane carboxylic acids in effective manner is industrially important.
The presently known major method for production of (+)-isomers is organosynthetic optical resolution, but development of more economical methods for optical resolution is now desired for production of (+)-isomers because the organosynthetic optical resolution requires a relatively expensive optically active reagent or a complicated step. There are known methods for producing optically active (+)-trans acid by resolving cyclopropane carboxylates by asymmetric hydrolysis with a pig liver esterase (e.g., Schneider et al., Angewande chemie International Edition in English 23. 64 (1984)) or with a microbial esterase (Japanese Patent Publication (Kokai) No. 244295/1985).
However, the former method is industrially disadvantageous because of the expense and limited supply of the pig liver esterase. As for the latter method, it is reported that the trans-isomer of cyclopropane carboxylic acid ester is preferentially resolved by asymmetric hydrolysis but the method can not be industrially applied because the yield of (+)-trans-cyclopropane carboxylic acid is as low as 31 mg/100 ml culture medium, and the concentration of the substrate and the optical purity of the resulting (+)-trans cyclopropane carboxylic acid are low.